Electric heater



Oct. 9, 1934. Bfi g 1,976,652

ELECTRIC HEATER Original Filed Aug. 27. 1931 2 Sheets-Sheet l Oct. 9,1934. Q BRANTINGHAM 1,976,652

ELECTRIC HEATER Original Filed Aug. 27, 1931' 2 Sheets- Sheet 2 17AELHIHIIHHII) llill: fl rlrl it ,23 2'7 Z3 13 Patented Oct. 9, 1934PATENT ELECTRIC HEATER Alan Brantingham, Rockford, 111., assignor, bymesne assignments, to Faries Manufacturing Company, Decatur, IlL, acorporation of Illinois Application August 27, 1931', Serial No. 559,736

Renewed August 24, 1933 9 Claims. (01. 219--39) This invention relatesto electric heaters of the type employing a fan to circulate the air asit is heated, and constructed to permit operating the fan at high speedwithout the heating unit, for cooling purposes.

One of the objects of my invention is to generally improve theconstruction and operation of electric heaters of the type described.

Another object is to embody in an electric heater of this type certainunits of assembly enabling production at low cost of manufacture andenabling theseparate units to be tested and, if necessary, adjustmentsto be made before final assembly of said units into the heater as awhole. Another object ofmy invention is to provide a heater and fanwhich may be operated with safety around children. The fan and heatingelements are both completely guarded by casings and grills. The casingsof heaters of this type usually become so heated that one is apt to beburned, or at least experience some shock and discomfort, by coming incontact therewith accidentally, and, of course, this makes it necessaryto provide handles thereon to permit their being moved about. In myheater, which is also intended for portable use, the interiorconstruction is so designed that during operation the outer casing orshell remains sufficiently cool to eliminate the hazard mentioned, andpermit han- 80 dling thereof without the use of unsightly handles.

Another feature of my inventionis the provision of supporting meansforre'sistance wires which space them in parallel fashion and apportionequal lengths of resistance wire between the insulators. F

Other objects of the invention which relate more to the detailedconstruction will be brought out in the description in which referenceis made to the accompanying drawings, wherein- .40 Figure 1 is a frontelevation of the heater;

Fig. 2 is a vertical section taken on' the line 2-'-2 of Fig. 1; i

Fig. 3 is a section taken on the line3--3 of Fig. l; g i

Fig. 4 is a vertical section taken on the line 4-4 of Fig. 2; and I Fig.5 is a' vertical section'taken on the line 5 5 of Fig. 2. V

This application is a continuation in part of my application Serial No.536,334, filed May 11, 1931.

Referring to Fig. 2, 11 indicates the front plate of the heating unitand 12 the back or motor assembly plate. These plates are spaced' apartby a casing or band 13 having legs 14 attached thereto by bolts 15. Thefront plate 11 has a substantially square opening 16 for the passage ofheated air, said opening being covered from the inside with a wirescreen or grill 1?. The heating element 18, which is in the form of acrimped ribbon of resistant material, is threaded up and down and spacedevenly over practically the entire opening 16, as clearly shown in Fig.5. The ends of the ribbon are looped around the insulator spools 19 andwelded to the end coils as at 20. The correct spacing is effected by theinsulator spools 19 being mounted on supporting plates 21 by means ofcotter pins 22. This arrangement of the heating element provides uniformlength of ribbons between insulators and in assembling, each coil isgiven the same tension. This prevents sagging and distortion of theribbon during operation because all of the ribbons will expand alike.The insulator supporting plates 21 and the wire grill 1'7 are held tothe front plate 11 by lock nuts 23 which are threadedly mounted on studsor tie bolts 24 which thread into the front plate at points 25 wherethickness of material is provided by the ornamental design of thefaceplate. Strips of heat insulating material. 26 are interposed betweenthe insulator supporting plates 21 and the grill 1'! for the purpose ofchecking the transmission of heat by conduotion from the heating elementto the face plate 11 which otherwise might burn or discolor 35 thefinish. The insulator supporting plates 21 have inwardly bent flanges 27which serve as deflectors to direct the air from the fan 28 around theinsulators and out the front opening 16, thereby cooling the insulators.

The fan 28 is driven by the motor 29 which is mounted substantially inthe center of the back plate as clearly shown in Fig. 4, by bolts 31entered in a Y-shaped rib 32 integral with the back plate 12. This backplate has openings 33 which 9 are covered by an expanded metal screen orgrill 30 interposed between and held in place by the motor 29- and therib '32. A three position switch 34 is also mounted on the rib 32beneath the motor. The lead-in wire 35, guarded. by an insulator thimble36, enters the heater directly beneath the switch.

The split casing or band 13 to which the legs is are attached is joinedat the bottom by the bolts 37 entered through the downwardly turnedflanges 38. The upper half of the casing is lined on the inside with aheat insulating material 39 to prevent this thin-wall casingfrom'becoming sufficiently heated to be dangerous.

The motor, switch and wiring plan used in this 110 unit have all beenfully disclosed in my copending application, Serial No. 536,334, filedMay 11, 1931, and need not be further described other than to say thatat one position of the switch the motor and heating element areconnected in series, the fan turning only fast enough to carry the heataway from the heating element. At the second position of the switch, nocurrent flows. At the third position the motor operates at high speed,delivering air for the purpose of any ordinary electric fan. In thisheating element is disconnected.

The method of assembling the above described parts is as follows: Theinsulator supporting plates 21 with the insulator spools 19 attached,

position the the front plate 11, the grill 17, and the heat insulatorstrips 26 are assembled as one unit and held together by the stud bolts24 and nuts 23.

The resistance ribbon 18 is then threaded in place,

the ends doubled back and welded, leaving sufficient. length of ribbonat the ends to be connected to wires. The heating unit being completemay be tested atthis stage of assembly.

The motor 29 together with the switch 34 and the grill 30 are assembledon the back plate 12. All the necessary wire connections may now be madewith exception of the two heater coil lead wires 41 and 42. This unit isnow complete and may be tested. After this the lead wires 41 and 42 maybe fastened to the ends of the resistance ribbon 18 by means of thebolts 43, this preferably being done during final assembly of theyheater units. The studs 24 projecting rearwardly from the front plate 11are passed through holes in the back plate 12 and nuts 44 are placedloosely thereon. The casing or band 13 with the legs afiixed thereto isthen spread sufficiently to encircle the front and back plate and whendrawn together at the bottom and held with bolts 37, said band seats inrecessed annular shoulders 45 and 46 in front and back plates 11 and 12,respectively. The nuts 44 are then tightened, drawing the front and backplates tight to the casing 13 which also serves as a spacing collar.From the foregoing it will be seen that I have provided an electricheater made up principally of three units of assembly, one which may betermed a front plate unit of assembly comprising a front plate and theheating unit parts held in operative relation by means of tie bolts,anothera back plate unit comprising a back plateand an electric motorand fan mounted thereon, and a thirda casing unit comprising a bandencircling the parts carried between the front and back plate units,said tie bolts serving to hold the front and back plate units togetherin position on the casing unit. In the preferred embodiment of myinvention herein disclosed, the back plate unit is drawn into positionby means of nuts on the tie bolts, although it will be understoodthat inpractice, equivalent means might be used for this purpose. Anotherfeature in connection with the preferred embodiment is the provision oflegs mounted directly on the casing unit for the pur-' pose ofsupporting the heater as a whole. Another feature is the constructionand arrangement of the insulator supporting plates and theuse of theseplates as deflectors for directing the air blast past the insulatorsupports for cooling them. These and other features described intheforegoing specification make for simplicity in design and constructionand are factors both in the low cost of manufacture of the parts, aswell as in the low cost of assembling such parts. Further? more, aheater'embodylng the features herein disclosed may be produced in anattractive ornamental design and be so constructed that it will servevery efiiciently the purposes of heating or of cooling as the case mayrequire.

It is believed the foregoing description conveys a good understanding ofall the objects and advantages of my invention. The appended claims havebeen drawn with a View of covering all legitimate modifications andadaptations.

I. claim:

1. In a motor driven fan, in combination, a heating unit, a front plateon which said heating unit is mounted, a back plate, a motor driven fanmounted on said back plate, the heating unit being completely assembledon the front plate and the fan being completely assembled on the backplate, said plates having openings to permit passage of'air moved bysaid fan, a casing encircling the front and back plates and serving onlyto hold them in spaced relation, means for drawing the front and backplate toward each other, whereby to clamp the casing therebetween so asto form a rigid unit, and means for supporting said casing so as tosupport the rest of the unit thereby. v

2. In an electric heater, in combination, a front plate having anopening for the passage of heated air, an open-work grill covering saidopening, insulators, supports to which said insulators-are attached,resistance wires strung upon and between said insulators, heatinsulating material between said grill and insulator supports, and meansserving to fasten both the grill and the insulator supports to the frontplate. $3. In an electric heater, in'combination, a motor driven fan, afront plate having a substantiallyrectangular opening providedthereinfor the passage of an air blast from said fan, a pair ofinsulator supports mounted on said front plate parallel to each other onopposite. sides of said opening, insulators attached to said insulatorsupports, resistance-wires strung between said insulators, the length ofthe resistance wires between insulators being substantially equal andtraversingsubstantially the entire area of said opening in the frontplate.

' 4. In an electric heater, in combination, a motor driven fan, a frontplate having an opening for the passage of an air blast from said fan, apair of insulator supports mounted on said front plate parallel to eachother on opposite sides ,of'

said opening, insulators mounted on said insulator supports, resistancewires strung on said insulators, said insulator supports having flangesto direct and converge the air stream from said fan into the areatraversed by the insulators.

5. In an electric heater, in combination, a front plate assemblycomprising a. front plate having a central opening, a grill coveringsaid opening and positioned against the plate, insulator supportspositioned against and insulated from the grill and equipped withinsulator spools; tie bolts fastened tothe front plate and serving tohold the grill and insulator plates in position, and resistance ribbonstrung back and forth onsaid insulator spools; a back plateunitcomprising a back plate having a central opening for the passage ofair, a grill covering said opening and an electric motor and fan mountedon the back plate, the back plate unit being adapted to be held inposition on the tie bolts of the front plate unit; and a casing unitcomprising a band adapted to be interposed between the front and backplate units and to encircle the structure carried there: byfand to holdsaid plates in spaced relation,

said units being clamped to the band and in fixed relationship by meansof nuts on said tie bolts.

6. In an electric heater, in combination, a front plate unit of assemblycomprising a front plate having an opening for the passage of air, aplurality of insulator supporting plates each equipped with a series ofinsulator spools, tie bolts serving to fasten said insulator supportingplates to the frontplate, and a resistance ribbon strung back and forthon said insulator spools; a back plate unit of assembly comprising a.back plate and an electric motor and fan mounted thereon, the back plateadapted to be mounted on said tie bolts; and a casing unit adapted to beinterposed between and upon said'front and back plates for holding themin spaced relation; and means on the tie bolts holding said units inposition.

7. In an electric heater, in combination, a front plate having a centralopening for the passage of air, a plurality of insulator supportingplates mounted on the inner side of said front plate and each equippedwith a series of insulator spools, a resistance ribbon strung back andforth on said insulator supports, and an electric motor and fan forproducing a blast of air past the heater formed by said resistanceribbon, said supporting plates having deflector flanges extending in thepath of the air blast and serving to deflect and converge the air blastinwardly past the insulators through the opening in the front plate.

8. In an electric heater, in combination, a front plate having a centralopening for the passage of air, insulator spools carrying resistanceribbon constituting the heating element, means supporting the insulatorspools comprising a supporting plate structure having a deflectorarranged to direct an air blast from an electric motor fan past theinsulator spools and through the heating unit and the opening in thefront plate, and an electric motor and fan for producing said air blast.

9. In an electric heater, in combination, a front plate unit of assemblycomprising a front plate having an opening for the passage of air, andan electric resistance element traversed across said opening; a backplate unit of assembly comprising a back plate and an electric motor andfan mounted on the back plate; a casing unit comprising a longitudinallysplit band interposed between and encircling the structure of said frontand back plate units and adapted to be seated on shoulders provided onsaid units and to hold them in spaced relation, said casing unit beingequipped with legs serving to support the entire heater; means fordrawing the front and back plate units toward each other to clamp theinterposed casing unit therebetween, and means for contracting the splitband forming the casing unit, whereby to firmly engage the shoulders onthe front and back plates.

. ALAN BRANTINGHAM.

